[time-nuts] 10811 foam enclosure

WarrenS warrensjmail-one at yahoo.com
Sun Jan 9 20:59:40 UTC 2011

A simple box is fine for many Tbolt applications.

Much depends on the TBolt Osc and what setting you have, especially the TC 
and damping.
With the factory default setting you can pretty much put the thing in an 
outside unsheltered shed and have it work OK,
But it will not be the best it can be.
The object is to slow the frequency control loop down as much as possible so 
it does not transfer the short term GPS noise to the osc.
The slower the temperature changes the less the loop has to work and the 
higher the TC can be set.

Do the same test with the Tbolt's TC set to 1000 seconds, damping to 1.2 
and watch the phase error using Lady Heater.
You'll see BIG BIG differences based on the rate of change of the 



Mark Spencer mspencer12345 at yahoo.ca  wrote:

My experiences placing my thunderbolt board in various insulated containers 
show little or no improvement over simply putting a cardboard box over it to 
keep drafts away.   As time allows I'm going to re run some of the tests 
using my 5370 and an external standard vs relying on the data from the 
thunderbolt itself but I'm not expecting to see any significant changes.

I've also started to run some tests with disciplining turned off on the 
thunderbolt and the drift of the ocxo is quite apparent.

I'll likely get a heavy die cast box for my thunderbolt at some point.

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